ABSTRACT
Objective: To further investigate the molecular mechanism of photodynamic therapy. Methods: We used cDNA microarray technique to explore the gene expression profiles of HEPG2 cells after photodynamic therapy with hematoperphyrin monomethyl ether(HMME) in HEPG2 cells. After treated with HMME for 60 min, the HEPG2 cells were irradiated with laser, and observed by microscope with H E staining. To prepare the probes, mRNA from both control and treated cells were isolated and purified, then reversely transcribed to cDNA with the incorporation of fluorecent labeled dUTP. The probes were hybridized with a cDNA microarray representing the 1 538 genes originated from human hepatocarcinoma cells. The fluorencent signals of Cy3 and Cy5 were scanned and analyzed. Results: After laser irradiation, the HEPG2 cells showed the typical feature of apoptosis. The gene expression profiles were also changed greatly. Among the 1 538 target genes, 389(2.47%) different expression genes were detected. Most of the changed genes (nearly 80%) were down regulated. They were functionally related to cell proliferation cycle, replication, metabolism and so on. Several apoptosis associated genes were detected among those up regulated genes, encoding the key proteins involved in apoptosis signal transduction, such as CCP32,AIF,Mch2. Conclusion: The HMME photodynamic therapy can initiate the apoptosis process of HEPG2 cells, which may be regulated by mitochondial pathway.[